In industrial applications, such as in glass melting furnaces, the ability to continuously and accurately measure the oxygen content of the combustion gases is an invaluable aid in obtaining optimum utilization of fuel. Constant monitoring of the oxygen level also allows for increased stability of a melting process, particularly in glass melting applications where such monitoring can influence the melting rates, fining and refractory corrosion rate, and can ultimately improve glass quality.
Oxygen sensing devices mounted in furnace walls for in situ monitoring of oxygen is known in the prior art. In general these devices have required the elaborate housing of the sensing device to protect it from the furnace environment and from movement, loosening or cracking of the probe. The latter can occur during mounting or as a result of the differing thermal expansion and contractions of the sensing device and its protective casing.
A simple structure for mounting an oxygen sensor probe for in situ monitoring of oxygen levels within a furnace wall has been a difficult problem to solve. This is especially true in glass melting regenerative furnace where there is extensive thermal cycling and the solid electrolyte tube becomes subject to cracking due to thermal shock.